TY - JOUR
T1 - Synthesis and characterization of aliphatic ammonium ionenes
T2 - Aqueous size exclusion chromatography for absolute molecular weight characterization
AU - Layman, John M.
AU - Borgerding, Erika M.
AU - Williams, Sharlene R.
AU - Heath, William H.
AU - Long, Timothy E.
PY - 2008/7/8
Y1 - 2008/7/8
N2 - Cationic aliphatic ammonium polyionenes, specifically 12,12- and 6,12-ionenes, were synthesized using step-growth polymerization and aqueous-based size exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) revealed absolute molecular weight information. The chromatographic separation of cationic polyelectrolytes presents many additional challenges compared to SEC of nonassociating, neutral polymers. Therefore, an aqueous-based SEC-MALLS mobile phase composition was identified to separate these notoriously challenging polyelectrolytes in an effort to achieve absolute molecular weight analysis. Various solvent compositions were evaluated for their ability to solvate and reproducibly separate both 6,12- and 12,-12-ionenes. Dynamic light scattering (DLS) verified the absence of aggregation of polyionenes in preferred mobile phase compositions. The optimum solvent composition comprised a ternary mixture of 54/23/23 water/methanol/glacial acetic acid, 0.54 M NaOAc, at a pH of 4.0. Weight-average molecular weights for the synthesized ammonium 12,12-ionenes ranged from 11 000 to 40 000 g/mol, and ammonium 6,12-ionenes had weight-average molecular weights ranging from 19 000 to 49 900 g/mol. Mark-Houwink parameters were also determined for both the 12,12- and 6,12-ionenes in the optimum mobile phase using an online capillary viscometer.
AB - Cationic aliphatic ammonium polyionenes, specifically 12,12- and 6,12-ionenes, were synthesized using step-growth polymerization and aqueous-based size exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) revealed absolute molecular weight information. The chromatographic separation of cationic polyelectrolytes presents many additional challenges compared to SEC of nonassociating, neutral polymers. Therefore, an aqueous-based SEC-MALLS mobile phase composition was identified to separate these notoriously challenging polyelectrolytes in an effort to achieve absolute molecular weight analysis. Various solvent compositions were evaluated for their ability to solvate and reproducibly separate both 6,12- and 12,-12-ionenes. Dynamic light scattering (DLS) verified the absence of aggregation of polyionenes in preferred mobile phase compositions. The optimum solvent composition comprised a ternary mixture of 54/23/23 water/methanol/glacial acetic acid, 0.54 M NaOAc, at a pH of 4.0. Weight-average molecular weights for the synthesized ammonium 12,12-ionenes ranged from 11 000 to 40 000 g/mol, and ammonium 6,12-ionenes had weight-average molecular weights ranging from 19 000 to 49 900 g/mol. Mark-Houwink parameters were also determined for both the 12,12- and 6,12-ionenes in the optimum mobile phase using an online capillary viscometer.
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U2 - 10.1021/ma800549j
DO - 10.1021/ma800549j
M3 - Article
AN - SCOPUS:47949105062
SN - 0024-9297
VL - 41
SP - 4635
EP - 4641
JO - Macromolecules
JF - Macromolecules
IS - 13
ER -